The invention relates to a device for detecting the internal temperature of a foodstuff, in particular a device for detecting a degree of doneness of a piece of meat to be prepared, according to the overarching concept of claim 1. The invention further relates to a method of preparing a foodstuff by a cooking process, in particular a grilling process.
When foodstuffs are cooked, the temperature and the length of the preparation are usually determined by the type of foodstuff and the desired final degree of doneness. In fish, usually a short preparation time suffices; for example, if you want to cook tuna lightly pink. In turn, for lamb and beef, there is a wide range of possible preparation, or the desired final degree of doneness. For example, for beef steaks, the desired final degree of doneness is called by the names “Blue Rare”, “Rare”, “Medium Rare”, “Medium”, “Medium Well”, and “Well Done”, the most common method of preparation being “Medium Rare”. Since steaks usually have a certain minimum thickness, namely preferably at least 2.5 cm (1 inch), better 3.8 cm (1.5 inches) or even better 5 cm (2 inches), it is often difficult to judge the doneness in the inside of the steak, because even a slight deviation with respect to the temperature of heating or duration of cooking may substantially change the final degree of doneness. In contrast, with other kinds of meat, for example chicken, pork or mutton, usually a thorough and complete cooking is desired. Should the pieces to be prepared also exceed a certain thickness, it is difficult to verify whether the inside of the pieces is already thoroughly cooked, or should be heated for an additional time.
Temperature-measuring devices for determining the temperature inside a food product are known in various designs. For example, the generic DE 20 2006 004 171 U1 discloses a testing device for determining the edibility of a food product, having a temperature-sensitive measuring probe, which is inserted into a food product, where several measuring sensors are arranged along the measuring probe such that the temperature values can be determined at various positions in the food. At the end of the measuring probe, there is provided a housing, which evaluates the sensor signals, and indicates by means of light-emitting diodes, whether all temperature values that were determined by the measurement sensors are above a set point.
This testing device cannot remain in the food during cooking, because the electronics arranged in the housing are sensitive to temperature. For each testing procedure, the testing device needs to be inserted into the food, for which the food must be removed from the grill, from the pan or the oven.
Since this is cumbersome, this testing device is suitable only for the purpose described, namely, for checking whether a food product is thoroughly cooked, but not for the determination of a more defined cooking state, e.g., only partial cooking of the food.
Furthermore, in the prior art, ovens are known that are equipped with a sensing element in the cooking chamber, which can be inserted into a food product and then controls heating of the oven as a function of the temperature in the core area of the food. DE 44 21 373 A1 discloses such an oven with a sensing element, whose electronic components are mounted in the tip, which is to prevent overheating of the electronic components. DE 44 21 373 A1 further discloses that the sensing element allows wireless transmission of the temperature signal, wherein for this purpose, alternatively, a radio transmitter, ultrasonic transmitter or optical transmitter is provided. However, the sensing element can only be operated with the oven, since the temperature signal is analyzed by the oven, and is not readable at the sensing element itself.
Furthermore, in the prior art, there are known still mechanically operating measuring devices, which, it is true, have a sufficient thermal resistance to remain in place in the foodstuff during the preparation. However, they are not accurate or sufficiently discriminating to allow the preparation of a foodstuff towards a well-defined degree of doneness. The precision of the temperature-measurement sensor and the exact indication of achieving at least one degree of doneness are crucial for the result of preparation, i.e., the final degree of doneness.
The underlying task of the invention is thus to provide a versatile device of the initially indicated type, which operates autonomously, i.e., without additional equipment, and reports the achieving of a foodstuff's precise doneness.